For interested parties IOMMU development was pushed little bit forward. We plan to release it in v18.104.22.168.
You can read more here:
is it possible to get automatic information via old-school e-mail, if a new version is released?
I'm sorry but we don't have MailChimp configured. There were some plans in the past but we are working on other issues. I will try rise priority of that task and see if I can integratedit on https://pcengines.github.io.